Vertical milling machines are well known in the art; their use is for vertical milling of a part held on a horizontal bed. To increase the flexibility of the milling machine, an operator connects a right angle adaptor to the head of the milling machine to permit an operator to mill or drill horizontally. To drill horizontally, an operator working on a piece places it on the conventional milling machine bed which he or she can then move horizontally or vertically. To drill into an article, an operator moves the bed containing the work piece into the horizontally rotating drill. One of the disadvantages of using right-angle adaptors to is that an operator must move the entire bed and the work piece into the rotating drill. The disadvantage of moving the bed is that, because the bed is massive and moves through a set of reduction gears, an operator oftentimes loses the feel of moving the bed and thus has difficulty in the moving the bed delicately and precisely; consequently, an operator may break the drill bit in the work piece.
It would be advantageous if an operator could drill holes in a work piece on the bed of a vertical milling machine with the feel-sensitive movement typically used to drill holes in a drill press. In addition, tapping a hole with conventional right angle adaptors is virtually impossible because an operator can not precisely move the bed into a tap located in the right-angle adaptor of the milling machine. A horizontally displaceable bed also limits an operator to drilling holes parallel to the horizontal displacement axis of the work bed.
The present invention eliminates the necessity of moving the part into the rotating tool because it provides a movable chuck, thus giving an operator a feel-sensitive horizontally movable chuck which he or she can precisely move into the work piece.
A further advantage is that an operator can now drill and tap horizontally at angles other than those parallel to the motion of the bed of the milling machine. In addition, because the drive shaft is horizontally displaceable, the operator can use my invention to tap holes in work pieces located on the bed.